The research consists of eight projects, each with its own individual goals and objectives, but bound together by a common developmental theme. The studies all address some aspect of the manner in which development and eventual clinical outcome are influenced by intervening variables, and all share the ultimate goal of improving the care of people with clefts of the lip and palate by expanding our knowledge about a variety of factors that control or influence the results of treatment and by seeking ways to change treatment as the result of improved understanding. Post-natal development in individuals with clefts is the focus of our studies which share the common goal of discovering how various developmental factors are related to problems of the middle ear, audition, stature, and speech. The Speech Science Project is composed of seven related substudies and seeks to determine the roles played by a variety of physical, physiological, and developmental attributes with the ultimate goal being the development of a model of velopharyngeal valving. Understanding this important system will lead to improved methods of treating congenital abnormalities that affect it. The second group of studies consists of four projects which seek to determine either how certain relevant structures develop or how they are influenced by intervening variables. These studies incorporate animal or fetal material rather than human subjects, but they all have the goal of explaining how outcome may be influenced by developmental characteristics or by various forms of intervention.